The present invention relates to life preserving flotation devices and, specifically, to a foldable life preserving jacket and a pressure responsive switch for use with the jacket.
Many types of life jackets, such as those used on large vessels, are filled with cork, kapok, or other buoyant materials to provide a floating jacket which is ready for immediate use. Because such buoyant materials sometimes make the jacket bulky, there is a tendency not to wear the jacket until an actual need arises. When an emergency occurs, there are oftentimes some survivors in the water without life preserving devices. As a result, it is advantageous for a survivor wearing a life jacket to be able to share the jacket without unduly endangering the wearers own life.
Another problem is locating survivors in the sea. Some life preserving devices are equipped with radio transmitters which transmit a distress signal upon actuation by the wearer in an emergency. Because such devices are used in times of great stress, there can be no time wasted fumbling with latches, pins or cords in order to make the survival device operative. In the case of an airplane crash, the survivor might be unconscious in the water and be unable to actuate the radio transmitter or other survival device associated with the jacket.
U.S. Pat. No. 3,041,021 to Jaffe, issued June 26, 1962, shows a life jacket with a radio receiver affixed to the jacket. The radio receives continuously transmitted signals from a transmitter on the vessel. Should the wearer fall off the vessel into the water and be separated by more than a fixed distance from the vessel transmitter, a solenoid in the radio receiver is actuated and inflates the life jacket. The system is not intended to work in the situation where the vessel is itself in danger.
U.S. Pat. No. 3,798,692 to Madeley, issued Mar. 26, 1974, shows a life jacket with a pressure responsive switch which actuates light on the life jacket when the wearer falls into the water. The pressure switch is actuated in response to contact with the water pressure of the surrounding water. The actuation device does not actuate a radio transmitter.
U.S. Pat. No. 3,095,568 to Aine, issued June 25, 1963, shows a life preserver with a pneumatic antenna erecting apparatus. Gas pressure is used to erect a mast or antenna for transmitting radio signals by a radio carried on the life preserver. The radio transmitter is not automatically actuated in response to inflation pressure.
There exists a need, therefore, for a life preserver which can be used by more than one person without endangering the life of the primary wearer.
There exists a need for a life preserving device of the type having a radio transmitter affixed thereto which incorporates a pressure responsive switch for automatically actuating the radio transmitter in response to inflation pressure.
Additional objects, features and advantages will be apparent in the written description which follows.